Root Complex Event Collectors (RCEC) appear as peers to Root Ports and may
also have the AER capability.

Add RCEC support to the AER error injection driver.
Co-developed-by: NSean V Kelley <sean.v.kelley@intel.com>
Link: https://lore.kernel.org/r/20201121001036.8560-16-sean.v.kelley@intel.com
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> # non-native/no RCEC
Signed-off-by: NQiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: NSean V Kelley <sean.v.kelley@intel.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: NKuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>